Don't probe Samsung LED conector with LED tester, connect may not make contact afterwards

[howardc64]

Samsung have been using this style LED connector for few years now



Usually good idea to test the LEDs before opening the panel to change them. I do this without the PSU stil connected. With this connector (white one) have to jam the LED tester probes in the very narrow thin slot where the PSU blade style male prong inserts into. I've done this on many Samsungs without problem until today...

The female terminal inside the white connector has fragile fingers that grabs onto the male blades on the PSU's black connector. If the LED tester probe spreads open the fingers (need to push the probe in with a little force to make contact) the fingers will no longer close around the PSU connector blades. Need to remove the white connector. De-pin the female terminals, squeeze the fingers tighter. De-pin also isn't easy, need a very narrow long tool to unlock the terminal pin and ideally 3 hands. I ripped 1 wire doing it by myself and required repair.

As if this is not enough, removing the LED wires ( to de-pin, repair wires etc) on this edge lit TV need to be retaped back carefully to ensure flat. Otherwise, will make a slight bump on the reflector paper and result in a light shadow (luckly only visible on solid light color screen tests)

Can't find the exact picture of the female prongs with fingers but looks similar to this. Instead of 1 tall finger in this pic, there are 2 shorter ones. And the fingers are much flimsy than this pic. Anyway, once spread open, need to de-pin prongs and squeeze the fingers tight again. PITA.


Does anyone know if its safe to leave PSU connected to the LED connector (not powered on of course) when testing backlight? It would make this a lot easier.

[Diah]

shit sammy they know this difficulty, that why put the design the way to check LED BL working by disconnecting MB from PSU, no m more or less

[howardc64]

shit sammy they know this difficulty, that why put the design the way to check LED BL working by disconnecting MB from PSU, no m more or less

Yes, disconnect MB to turn on backlight is easy. And its a good idea to use this method to keep backlight on while reinstalling all the diffusers to make sure no over bright regions.

I usually like to use LED tester on each LED circuit and read the voltage to confirm LED has failed. Unforunatly caused this connector problem on this style connector

[Diah]

don't trust the tester when the BL Edge one... by direct LED exclude LG and some brand can do... just because Edge one LED or Double one always there Zener Diode protection build in LED this will pass by tester if it defect same to Direct LED

[howardc64]

Got another 2 Samsung edge lit TVs with these connectors. Really like to test the LEDs without PSU before full disassembly (in case failure is PSU). Anyone know if safe to run LED tester with the PSU connected to the LED connector? Everyone showing how to use LED tester don't show this particular connector and its challenges.

Note its not possible to access the LED connector with PSU removed. Can jam the LED test probes in which will widen the connector clasps and no longer make contact to PSU connector. No access from the back of the connector (LED test probe handle too wide to enter straight on adjacent connections) I guess need to harvest one of these connectors from a dead PSU in the future.

I'm not suggesting to trust LED connector 100%, just like to a sanity check to make sure its not PSU before doing full tear down to expose the LEDs.

Of course it is most likely failed LED bar. I did encounter a curved TV where it was just loose connection at this connector. Simply remove and reinstall the PSU fixed the contact (and of course always try that first on these TVs)

[lotas]

Try to find a jumper with (+), if there is none, then find (-) there will be more of them, for each channel, cut it, them with nippers, test, then connect them together and solder with a drop of tin.

[howardc64]

Try to find a jumper with (+), if there is none, then find (-) there will be more of them, for each channel, cut it, them with nippers, test, then connect them together and solder with a drop of tin.

Thanks, I think jumpers are too big and will spread out the connector clasps. Need to find thinner blades.

I'll just gamble on bad LEDs on these 2 TVs and probably just salvage a connector out of a PSU for future.

[lotas]

Yes, you probably didn't understand me, I'm saying to cut the jumper with wire cutters, that is, cut off (disconnect) the connector from the backlight driver so that the power from the LED tester does not go to the LED driver board.

[howardc64]

Yes, you probably didn't understand me, I'm saying to cut the jumper with wire cutters, that is, cut off (disconnect) the connector from the backlight driver so that the power from the LED tester does not go to the LED driver board.

oh ok I understand now. Good idea. I closed the TV now waiting for replacement edge LED bar. Will try to desolder the jumpers when I open it again and post results.